The dataset contains excited-state photoemission band mapping data of the topological insulator Bi2Te2Se. Provenance; The measurements were carried out at the Fritz Haber Insititute of the Max Planck Society, Germany. The Bi2Te2Se sample was grown at Aarhus University, Denmark. The photoelectrons were detected using SPECS METIS 1000 3D detector with extreme UV pulses centered at 21.7 eV as probe and a pump light pulses centered at 800 nm, which populates part of the excited electronic states (i.e. first conduction band). Content: The dataset comes from (1) binning of the single-electron event data and (2) preprocessing through symmetrization and MCLAHE algorithm (https://ieeexplore.ieee.org/document/8895993) for contrast adjustment Usage: The dataset is the prerequisite for band structure reconstruction, which may be used for reproducing the results in (https://arxiv.org/abs/2005.10210). For reconstruction, see the source code and examples on GitHub (https://github.com/mpes-kit/fuller).